merkle-json

Computing the hash of JSON objects can be tricky because JSON.stringify()
does not have a guaranteed string representation of a Javascript object.
Specifically, the following are equivalent and valid outputs of JSON.stringify():

``js
var json = "{size:{w:100,h:200}}";
var json = "{size:{h:100,w:200}}";
`

MerkleJson guarantees a unique hash code for any Javascript object.
In addition, MerkleJson is efficient in that it only recalculates
object hashes if the object has no Merkle hash tag. If a Merkle hash
tag is present, its value is returned as the hash value of that object.

$3

Unlike JSON, MerkleJson serializes objects canonically.

`js
var obj = {
d:4,
b:2,
a:1,
c:3,
};
console.log(JSON.stringify(obj)); // {"d":4,"b":2,"a":1,"c":3}
var mj = new MerkleJson();
console.log(mj.stringify(obj)); // {"a":1,"b":2,"c":3,"d":4}
`

$3


`js
var mj = new MerkleJson();
var hash = mj.hash({
size:{
w:100,
h:200
}
}); // e77b735125fec27a61c6f54b17fb6221

var hash = mj.hash({
size:{ // hash is independent of property order
h:200
w:100,
}
}); // e77b735125fec27a61c6f54b17fb6221
`


$3


`js
var mj = new MerkleJson();
var useMerkleHash = true;
var hash = mj.hash({
any1: thing1,
any2: thing2,
any3: thing3,
}, useMerkleHash); // 441e4f8dabdc6cb17dc9500cee73155b

var hash = mj.hash({
... // anything
merkleHash: e77b735125fec27a61c6f54b17fb6221,
}, useMerkleHash); // e77b735125fec27a61c6f54b17fb6221

var useMerkleHash = false; // force hash calculation
var hash = mj.hash({
any1: thing1,
any2: thing2,
any3: thing3,
merkleHash: e77b735125fec27a61c6f54b17fb6221, // ignored
}, useMerkleHash); // 441e4f8dabdc6cb17dc9500cee73155b
``